Enable staticcheck linter. Disable check for folder /pkg and /test by now.

Signed-off-by: Xun Jiang <blackpiglet@gmail.com>

.github/workflows/pr-ci-check.yml

@@ -4,6 +4,8 @@ jobs:
   build:
     name: Run CI
     runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
     steps:
       - name: Set up Go
         uses: actions/setup-go@v2
@@ -27,3 +29,7 @@ jobs:
           token: ${{ secrets.CODECOV_TOKEN }}
           files: coverage.out
           verbose: true
+      - name: Run staticcheck
+        uses: dominikh/staticcheck-action@v1.3.0
+        with:
+          version: "2022.1.3"